A method and system for testing the resistance of nickel-plated battery cells based on Kelvin four-wire system

Abstract

This invention provides a method and system for testing the resistance of nickel plates in battery cells based on a Kelvin four-wire system. The method includes the following steps: Step S1: A PLC drives a camera via a servo motor to move above the battery cell, and the camera performs visual positioning of the nickel plates welded to the terminals of the battery cell to obtain a positioning result; Step S2: Based on the positioning result, the PLC drives a probe to press against the nickel plate; Step S3: The PLC first controls a current source to output a rated current to the nickel plate, and then collects the actual voltage of the nickel plate using a multimeter; Step S4: The PLC calculates the resistance of the nickel plate based on the rated current and the actual voltage, and performs welding quality verification based on the nickel plate resistance. The advantages of this invention are: it enables the testing of nickel plate resistance to determine the welding quality of the nickel plate, greatly improving the accuracy of battery pack management, service life, and safety.

Description

Technical Field

[0001] This invention relates to the field of battery cell testing technology, and in particular to a method and system for testing the resistance of nickel-plated battery cells based on the Kelvin four-wire system. Background Technology

[0002] With the rapid development of new energy vehicles, battery packs, which serve as the power source for these vehicles, are becoming increasingly diversified, and the safety of battery packs is receiving more and more attention, requiring high-precision management.

[0003] A battery pack is assembled from several cells and uses a laser welding CCS (Coll Contact System) to weld nickel strips onto the terminals of the cells to connect them in series and parallel. If the nickel strips and terminals are not fully bonded, the resistance of the nickel strips will be too high, which will lead to inaccurate data (voltage, temperature) collected by the battery management system (BMU), resulting in inaccurate management of the battery pack, reduced battery pack life, and even safety hazards.

[0004] However, traditionally, there is no method to test the resistance of nickel strips to determine welding quality. Therefore, how to provide a method and system for testing the resistance of nickel strips in battery cells based on the Kelvin four-wire system to determine the welding quality of nickel strips has become an urgent technical problem to be solved. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method and system for testing the resistance of nickel sheet in a battery cell based on the Kelvin four-wire system, so as to test the resistance of the nickel sheet and determine the welding quality of the nickel sheet.

[0006] In a first aspect, the present invention provides a method for testing the resistance of nickel-plated battery cells based on a Kelvin four-wire system, comprising the following steps:

[0007] Step S1: The PLC drives the camera to move above the battery cell via a servo motor. The camera then performs visual positioning of the nickel sheet welded to the electrode of the battery cell to obtain the positioning result.

[0008] Step S2: Based on the positioning result, the PLC drives the probe to press onto the nickel sheet;

[0009] Step S3: The PLC first controls the current source to output the rated current to the nickel sheet, and then uses a multimeter to collect the actual voltage of the nickel sheet.

[0010] Step S4: The PLC calculates the nickel sheet resistance based on the rated current and actual voltage, and performs welding quality verification based on the nickel sheet resistance.

[0011] Furthermore, step S1 specifically includes:

[0012] The PLC first controls the servo motor to reset, then drives the camera to move above the battery cell via the servo motor. The camera captures a photo of the battery cell, and the photo is analyzed using a visual positioning algorithm to visually locate the nickel sheet welded to the battery cell's terminals, thus obtaining the positioning result.

[0013] Furthermore, step S2 specifically includes:

[0014] Based on the positioning results, the PLC drives the needle bed to move via a servo motor, so that the probes connected to the current source and the multimeter are pressed onto the nickel sheet.

[0015] Furthermore, step S3 specifically includes:

[0016] The PLC controls the current source to output the rated current to the nickel plate by switching relays, and then collects the actual voltage of the nickel plate by using a multimeter.

[0017] Furthermore, step S4 specifically includes:

[0018] The PLC divides the actual voltage by the rated current to calculate the nickel sheet resistance, and verifies the welding quality of the nickel sheet based on whether the nickel sheet resistance is within the standard resistance range.

[0019] Secondly, the present invention provides a battery cell nickel sheet resistance testing system based on Kelvin four-wire system, comprising the following modules:

[0020] The visual positioning module is used by the PLC to drive the camera to move above the battery cell via a servo motor, and to perform visual positioning of the nickel sheet welded on the battery cell's terminals to obtain the positioning result.

[0021] The probe pressing module is used by the PLC to drive the probe to press onto the nickel sheet based on the positioning result;

[0022] The voltage acquisition module is used by the PLC to first control the current source to output the rated current to the nickel sheet, and then to acquire the actual voltage of the nickel sheet through a multimeter.

[0023] The nickel sheet resistance testing module is used by the PLC to calculate the nickel sheet resistance based on the rated current and actual voltage, and to perform welding quality verification based on the nickel sheet resistance.

[0024] Furthermore, the visual positioning module is specifically used for:

[0025] The PLC first controls the servo motor to reset, then drives the camera to move above the battery cell via the servo motor. The camera captures a photo of the battery cell, and the photo is analyzed using a visual positioning algorithm to visually locate the nickel sheet welded to the battery cell's terminals, thus obtaining the positioning result.

[0026] Furthermore, the probe pressing module is specifically used for:

[0027] Based on the positioning results, the PLC drives the needle bed to move via a servo motor, so that the probes connected to the current source and the multimeter are pressed onto the nickel sheet.

[0028] Furthermore, the voltage acquisition module is specifically used for:

[0029] The PLC controls the current source to output the rated current to the nickel plate by switching relays, and then collects the actual voltage of the nickel plate by using a multimeter.

[0030] Furthermore, the nickel sheet resistance testing module is specifically used for:

[0031] The PLC divides the actual voltage by the rated current to calculate the nickel sheet resistance, and verifies the welding quality of the nickel sheet based on whether the nickel sheet resistance is within the standard resistance range.

[0032] The advantages of this invention are:

[0033] A PLC uses a servo motor to drive a camera to move above the battery cell, visually positioning the nickel strip welded to the cell's terminals. Based on this positioning, a current source and multimeter probes are pressed onto the nickel strip. The PLC then controls the current source to output the rated current to the nickel strip, while the multimeter collects the actual voltage of the nickel strip. The resistance of the nickel strip is calculated based on the rated current and actual voltage, and the welding quality is verified based on this resistance. In essence, the current source and multimeter are connected to the nickel strip using a Kelvin four-wire system. The resistance is calculated based on the rated current output by the current source and the actual voltage collected by the multimeter. The welding quality is verified by checking whether the resistance is within the standard resistance range. This method of testing the nickel strip resistance to determine the welding quality significantly improves the accuracy of battery pack management, lifespan, and safety. Attached Figure Description

[0034] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0035] Figure 1 This is a flowchart of a method for testing the resistance of nickel-plated battery cells based on the Kelvin four-wire system, according to the present invention.

[0036] Figure 2 This is a schematic diagram of the structure of a nickel-plated cell resistance testing system based on the Kelvin four-wire system according to the present invention. Detailed Implementation

[0037] The technical solution in this application embodiment has the following general idea: a current source and a multimeter are connected to the nickel plate based on a Kelvin four-wire system, and the resistance of the nickel plate is calculated based on the rated current output by the current source and the actual voltage collected by the multimeter, so as to realize the testing of the resistance of the nickel plate.

[0038] Please refer to Figures 1 to 2 As shown, a preferred embodiment of the present invention, a method for testing the resistance of nickel-plated battery cells based on a Kelvin four-wire system, includes the following steps:

[0039] Step S1: The PLC drives the camera to move above the battery cell via a servo motor. The camera then performs visual positioning of the nickel sheet welded to the electrode of the battery cell to obtain the positioning result.

[0040] Step S2: Based on the positioning result, the PLC drives the probe to press onto the nickel sheet;

[0041] Step S3: The PLC first controls the current source to output the rated current to the nickel sheet, and then uses a multimeter to collect the actual voltage of the nickel sheet.

[0042] Step S4: The PLC calculates the nickel sheet resistance based on the rated current and actual voltage, and performs welding quality verification based on the nickel sheet resistance. In practice, multiple points of the nickel sheet can be tested by switching relays.

[0043] Step S1 specifically involves:

[0044] The PLC first controls the servo motor to reset, then drives the camera to move above the battery cell via the servo motor. The camera captures a photo of the battery cell, and the photo is analyzed using a visual positioning algorithm to visually locate the nickel sheet welded to the battery cell's terminals, thus obtaining the positioning result.

[0045] Step S2 specifically involves:

[0046] Based on the positioning results, the PLC drives the needle bed to move via a servo motor, pressing the probes connected to the current source and multimeter onto the nickel plate. In other words, the servo motor drives the lead screw, thereby coordinating the camera and needle bed to move.

[0047] Step S3 specifically involves:

[0048] The PLC controls the current source to output the rated current to the nickel plate by switching relays, and then collects the actual voltage of the nickel plate by using a multimeter.

[0049] Step S4 specifically involves:

[0050] The PLC divides the actual voltage by the rated current to calculate the nickel sheet resistance. Based on whether the nickel sheet resistance is within the standard resistance range, the welding quality of the nickel sheet is checked. An alarm is triggered when the nickel sheet resistance exceeds the standard resistance range. That is, nickel sheet resistance = actual voltage divided by rated current.

[0051] A preferred embodiment of the present invention, a nickel-plated battery cell resistance testing system based on Kelvin four-wire system, includes the following modules:

[0052] The visual positioning module is used by the PLC to drive the camera to move above the battery cell via a servo motor, and to perform visual positioning of the nickel sheet welded on the battery cell's terminals to obtain the positioning result.

[0053] The probe pressing module is used by the PLC to drive the probe to press onto the nickel sheet based on the positioning result;

[0054] The voltage acquisition module is used by the PLC to first control the current source to output the rated current to the nickel sheet, and then to acquire the actual voltage of the nickel sheet through a multimeter.

[0055] The nickel sheet resistance testing module is used by the PLC to calculate the nickel sheet resistance based on the rated current and actual voltage, and to verify the welding quality based on the nickel sheet resistance. In specific implementations, multiple points of the nickel sheet can be tested by switching relays.

[0056] The visual positioning module is specifically used for:

[0057] The PLC first controls the servo motor to reset, then drives the camera to move above the battery cell via the servo motor. The camera captures a photo of the battery cell, and the photo is analyzed using a visual positioning algorithm to visually locate the nickel sheet welded to the battery cell's terminals, thus obtaining the positioning result.

[0058] The probe pressing module is specifically used for:

[0059] Based on the positioning results, the PLC drives the needle bed to move via a servo motor, pressing the probes connected to the current source and multimeter onto the nickel plate. In other words, the servo motor drives the lead screw, thereby coordinating the camera and needle bed to move.

[0060] The voltage acquisition module is specifically used for:

[0061] The PLC controls the current source to output the rated current to the nickel plate by switching relays, and then collects the actual voltage of the nickel plate by using a multimeter.

[0062] The nickel sheet resistance testing module is specifically used for:

[0063] The PLC divides the actual voltage by the rated current to calculate the nickel sheet resistance. Based on whether the nickel sheet resistance is within the standard resistance range, the welding quality of the nickel sheet is checked. An alarm is triggered when the nickel sheet resistance exceeds the standard resistance range. That is, nickel sheet resistance = actual voltage divided by rated current.

[0064] In summary, the advantages of this invention are as follows:

[0065] A PLC uses a servo motor to drive a camera to move above the battery cell, visually positioning the nickel strip welded to the cell's terminals. Based on this positioning, a current source and multimeter probes are pressed onto the nickel strip. The PLC then controls the current source to output the rated current to the nickel strip, while the multimeter collects the actual voltage of the nickel strip. The resistance of the nickel strip is calculated based on the rated current and actual voltage, and the welding quality is verified based on this resistance. In essence, the current source and multimeter are connected to the nickel strip using a Kelvin four-wire system. The resistance is calculated based on the rated current output by the current source and the actual voltage collected by the multimeter. The welding quality is verified by checking whether the resistance is within the standard resistance range. This method of testing the nickel strip resistance to determine the welding quality significantly improves the accuracy of battery pack management, lifespan, and safety.

[0066] While specific embodiments of the present invention have been described above, those skilled in the art should understand that the specific embodiments described are merely illustrative and not intended to limit the scope of the present invention. Equivalent modifications and variations made by those skilled in the art in accordance with the spirit of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for testing the resistance of nickel-plated battery cells based on the Kelvin four-wire system, characterized in that: Includes the following steps: Step S1: After the PLC controls the servo motor to reset, it drives the camera to move above the battery cell through the servo motor. The camera captures a photo of the battery cell, and the photo is analyzed by a visual positioning algorithm to visually locate the nickel sheet welded on the electrode of the battery cell and obtain the positioning result. Step S2: Based on the positioning result, the PLC drives the needle bed to move via a servo motor so that the probes connected to the current source and the multimeter are pressed onto the nickel sheet. Step S3: The PLC controls the current source to output the rated current to the nickel sheet by switching relays, and then collects the actual voltage of the nickel sheet by using a multimeter. Step S4: The PLC calculates the nickel sheet resistance based on the rated current and actual voltage, and performs welding quality verification based on the nickel sheet resistance.

2. The method for testing the resistance of nickel-plated battery cells based on Kelvin four-wire system as described in claim 1, characterized in that: Step S4 specifically involves: The PLC divides the actual voltage by the rated current to calculate the nickel sheet resistance, and verifies the welding quality of the nickel sheet based on whether the nickel sheet resistance is within the standard resistance range.

3. A battery cell nickel sheet resistance testing system based on Kelvin four-wire system, characterized in that: Includes the following modules: The visual positioning module is used by the PLC to first control the servo motor to reset, and then drive the camera to move above the battery cell through the servo motor. The camera captures a photo of the battery cell, and the visual positioning algorithm analyzes the photo of the battery cell to visually locate the nickel sheet welded on the electrode of the battery cell and obtain the positioning result. The probe pressing module is used by the PLC to drive the needle bed to move via a servo motor based on the positioning result, so that the probes connected to the current source and the multimeter are pressed onto the nickel sheet. The voltage acquisition module is used by the PLC to control the current source to output the rated current to the nickel sheet by switching relays, and then to acquire the actual voltage of the nickel sheet by a multimeter. The nickel sheet resistance testing module is used by the PLC to calculate the nickel sheet resistance based on the rated current and actual voltage, and to perform welding quality verification based on the nickel sheet resistance.

4. The cell nickel sheet resistance testing system based on Kelvin four-wire system as described in claim 3, characterized in that: The nickel sheet resistance testing module is specifically used for: The PLC divides the actual voltage by the rated current to calculate the nickel sheet resistance, and verifies the welding quality of the nickel sheet based on whether the nickel sheet resistance is within the standard resistance range.

Images